Shrinkage of collagen

Lennox, F. G.

doi:10.1016/0006-3002(49)90090-6

Cited by 81 publications

(27 citation statements)

References 15 publications

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“…We have long known that isotonic constraints (i.e. constant load, including zero) affect the evolving shrinkage of heated collagenous tissues (Lennox 1949). Not surprisingly, we found that increasing durations of heating caused the morphology and birefringence of thermally treated traction-free tissues to evolve to the point of severe thermal coagulation and total loss of birefringence (see Fig.…”

Section: Discussionmentioning

confidence: 71%

“…Thus, our low and high-stretch constraints likely bracketed the in vivo range. The effects of mechanical constraints on the thermal damage of soft tissue are manifold: they may alter the socalled shrinkage temperature (Lennox 1949), delay the onset of shrinkage at a set temperature (Chen et al 1998;Harris and Humphrey 2004), reduce biaxial equilibrium shrinkage , or modulate biaxial mechanical properties Wells et al 2004). There has been little attempt to correlate gross changes in metrics of damage with histological evidence.…”

Section: Discussionmentioning

confidence: 99%

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Histological evidence for the role of mechanical stress in modulating thermal denaturation of collagen

Wells

Thomsen

Jones

et al. 2005

Biomech Model Mechanobiol

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The hyperthermia and thermal denaturation literatures reveal a time-temperature equivalency when heating cells or connective tissues: thermal damage increases with increasing temperature (for the same duration) and increases with increasing duration (for the same temperature). Recent findings conversely suggest that increasing the mechanical loading on a tissue during heating decreases the thermal damage (for a given temperature and duration of heating). Surprisingly, however, there are few histological correlates of such damage. In this paper, we show that progressive light microscopic changes - swelling of collagen bands, thickening of collagen-rich layers, hyalinization, and loss of birefringence approximately - correlate very well with both increased heating times and decreased mechanical loading. Increased mechanical stress is thus thermally protective and should be considered in the design of clinical procedures that use heating to treat diseases or injuries.

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Section: Discussionmentioning

confidence: 71%

Section: Discussionmentioning

confidence: 99%

Histological evidence for the role of mechanical stress in modulating thermal denaturation of collagen

Wells

Thomsen

Jones

et al. 2005

Biomech Model Mechanobiol

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“…In solution, individual monomers are thermally unstable (32). Within a fibril, monomers are thermally stabilized by lateral packing (30), and the denaturation temperature increases with mechanical loading (33). Furthermore, monomers within native collagen have disordered regions, and disorder is reduced by applied tensile strain (34,35).…”

Section: Possible Origin Of Internal Strain Energymentioning

confidence: 99%

Internal strain drives spontaneous periodic buckling in collagen and regulates remodeling

Dittmore

Silver

Sarkar

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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Fibrillar collagen, an essential structural component of the extracellular matrix, is remarkably resistant to proteolysis, requiring specialized matrix metalloproteinases (MMPs) to initiate its remodeling. In the context of native fibrils, remodeling is poorly understood; MMPs have limited access to cleavage sites and are inhibited by tension on the fibril. Here, single-molecule recordings of fluorescently labeled MMPs reveal cleavage-vulnerable binding regions arrayed periodically at ∼1-μm intervals along collagen fibrils. Binding regions remain periodic even as they migrate on the fibril, indicating a collective process of thermally activated and self-healing defect formation. An internal strain relief model involving reversible structural rearrangements quantitatively reproduces the observed spatial patterning and fluctuations of defects and provides a mechanism for tension-dependent stabilization of fibrillar collagen. This work identifies internal-strain-driven defects that may have general and widespread regulatory functions in selfassembled biological filaments.collagenase | matrix metalloproteinase | single molecule | pattern formation | mechanosensing C ollagen comprises over 30% of the protein mass of the human body and is an abundant structural protein in all animals (1). In its most common form, fibrillar collagen assembles from ∼300-nm polypeptide triple helices (tropocollagen) into highly organized, hierarchical networks that provide the protein scaffolding for the extracellular matrix, tendons, bones, and other load-bearing structures (1-3). The triple helix is highly resistant to proteolysis and collagen degradation requires a specialized class of proteases called matrix metalloproteinases (MMPs) (1, 4-6). Only four of the 23 human MMPs can initiate degradation of fibrillar collagen (6, 7). They cleave all three polypeptide chains of tropocollagen asynchronously at a unique thermally labile site located ∼225 nm from the N terminus (8, 9). MMPs play important physiological roles during development and wound healing, promoting cell motility, angiogenesis, and tissue remodeling (6,(10)(11)(12). MMP activity is regulated through gene expression and through binding of specific tissue inhibitors of metalloproteinase (13,14). In addition, MMP activity is regulated by mechanical stress on fibrillar collagen, which inhibits proteolysis through an unknown mechanism (15-17). Dysregulation of MMP activity is implicated in rheumatoid arthritis, atherosclerosis, tumor progression, and metastasis (13,18,19).Despite the importance of collagen remodeling for human health and disease, the mechanistic details of how MMPs degrade fibrillar collagen are not well established. Physiologically relevant collagen fibrils are heterogeneous and insoluble filamentous protein assemblies that are refractory to conventional biochemical analysis (20), yet a spatially extended substrate permits measurements of MMPs moving on fibrillar collagen through fluorescence correlation spectroscopy (20-22) and, more recently, direct single...

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“…Beyond this narrow thermal range, progressive denaturation occurs until there is complete fiber dissolution. 11 Partial thermal disruption of collagen's tightly maintained triple-␣ he-lical tertiary structure induces a phase transition necessitating contraction along the fiber's length (shrinkage), with a correlate increase in fiber diameter, much like the thickening seen by releasing tension on a taut rubber band. Early chemical studies reported that sheepskin collagen shrank in the 63°C to 67°C range, 11 intact rat-tail tendon in the 54°C to 59°C range, 12 human scleral collagen in the 61°C to 63°C range, and human corneal collagen in the 55°C to 59°C range.…”

mentioning

confidence: 99%

Ultrastructure of Collagen Thermally Denatured by Microsecond Domain Pulsed Carbon Dioxide Laser

et al. 1998

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Shrinkage of collagen

Cited by 81 publications

References 15 publications

Histological evidence for the role of mechanical stress in modulating thermal denaturation of collagen

Histological evidence for the role of mechanical stress in modulating thermal denaturation of collagen

Internal strain drives spontaneous periodic buckling in collagen and regulates remodeling

Ultrastructure of Collagen Thermally Denatured by Microsecond Domain Pulsed Carbon Dioxide Laser

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